Prognostic impact of global left ventricular hemodynamic afterload in severe aortic stenosis with preserved ejection fraction

Dissecting myocardial mechanics in patients with severe aortic stenosis: 2-dimensional vs 3-dimensional-speckle tracking echocardiography

Background

Aortic stenosis (AS) causes left ventricular (LV) pressure overload, leading to adverse LV remodeling and dysfunction. Identifying early subclinical markers of LV dysfunction in patients with significant AS is critical as this could provide support for earlier intervention, which may result in improved long-term outcomes. We therefore examined the impact of severe AS and its consequent increase in LV afterload on myocardial deformation and rotational mechanics by 2-dimensional (2D) and 3-dimensional (3D) speckle-tracking echocardiography.

Methods

We prospectively measured various strain parameters in 168 patients (42% female, mean age 72 ± 12 years) with severe AS and LV ejection fraction (EF) ≥50%, and compared them to normal values found in literature. 2D and 3D images were analyzed for global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), basal rotation, apical rotation, and peak systolic twist. We further assessed the degree of concordance between 2D and 3D strain, and examined their association with measures of LV preload and afterload.

Results

Patients with severe AS exhibited significantly lower GLS and GRS but higher GCS, apical rotation, and twist by 2D and 3D echocardiography compared with published normal values (P = 0.003 for 3D twist, P < 0.001 for all others). Agreement between 2D- and 3D-GLS by concordance correlation coefficient was 0.49 (95% confidence interval: 0.39–0.57). GLS was correlated with valvulo-arterial impedance, a measure of LV afterload (r = 0.34, p < 0.001 and r = 0.23, p = 0.003, respectively).

Conclusion

Patients with severe AS demonstrated lower-than-normal GLS and GRS but appear to compensate with higher-than-normal GCS, apical rotation, and twist in order to maintain a preserved LVEF. GLS showed a modest correlation with valvulo-arterial impedance.

Preprocedural valvuloarterial impedance as a predictor of left ventricular ejection fraction improvement after transcatheter aortic valve replacement in patients with reduced left ventricular ejection fraction

BACKGROUND

Predictors of left ventricular ejection fraction (LVEF) improvement after transcatheter aortic valve replacement (TAVR) in patients with a preoperative reduced LVEF are limited.

OBJECTIVES

This study aimed to investigate the relationship between preprocedural valuvuloarterial impedance (ZVa), which represents the global LV afterload, and LVEF improvement after TAVR.

METHODS

This was a single-center, retrospective study, which included patients with symptomatic aortic valve stenosis (AS) with a reduced baseline LVEF (< 50%) underwent TAVR. Based on the difference in the LVEF before and 1 month after the procedure, they were divided into two groups: improved group (≥ 10% improvement) and non-improved group (< 10% improvement or worsening). Preprocedural ZVa and clinical outcomes were then compared. ZVa was calculated using preprocedural transthoracic echocardiography data.

RESULTS

Among 473 cases of TAVR performed from May 2012 to July 2017 at Queen's Medical Center (Honolulu, HI, USA), 99 patients (improved group, n = 42; mean age 82.0 ± 8.6 years vs. non-improved group, n = 57, mean age 81.4 ± 9.5 years) were included. The improved group had a higher baseline ZVa {4.83 (4.15-6.89) mmHg/ml/m² vs. 4.04 (3.56-4.63) mmHg/ml/m², respectively, p = 0.0009} and prevalence of ZVa > 5 mmHg/ml/m² (45.2% vs. 17.5%, respectively, p = 0.0028). Multivariable analysis of predictors of LVEF improvement ≥ 10% at 1 month identified ZVa > 5 mmHg/ml/m² [odds ratio (OR): 3.31, 95% confidence interval (CI): 1.05-11.8] as a predictor. The improved group had a lower readmission rate due to heart failure than the non-improved group (log-rank test, p = 0.043).

CONCLUSION

In conclusion, Zva is a simple, noninvasive marker that shows promise as a predictor of LVEF improvement after TAVR in reduced LVEF patients.

The role of ventricular-arterial coupling in cardiac disease and heart failure: assessment, clinical implications and therapeutic interventions. A consensus document of the European Society of Cardiology Working Group on Aorta & Peripheral Vascular Diseases, European Association of Cardiovascular Imaging, and Heart Failure Association

Ventricular-arterial coupling (VAC) plays a major role in the physiology of cardiac and aortic mechanics, as well as in the pathophysiology of cardiac disease. VAC assessment possesses independent diagnostic and prognostic value and may be used to refine riskstratification and monitor therapeutic interventions. Traditionally, VAC is assessed by the non-invasive measurement of the ratio of arterial (Ea) to ventricular end-systolic elastance (Ees). With disease progression, both Ea and Ees may become abnormal and the Ea/Ees ratio may approximate its normal values. Therefore, the measurement of each component of this ratio or of novel more sensitive markers of myocardial (e.g. global longitudinal strain) and arterial function (e.g. pulse wave velocity) may better characterize VAC. In valvular heart disease, systemic arterial compliance and valvulo-arterial impedance have an established diagnostic and prognostic value and may monitor the effects of valve replacement on vascular and cardiac function. Treatment guided to improve VAC through improvement of both or each one of its components may delay incidence of heart failure and possibly improve prognosis in heart failure. In this consensus document, we describe the pathophysiology, the methods of assessment as well as the clinical implications of VAC in cardiac diseases and heart failure. Finally, we focus on interventions that may improve VAC and thus modify prognosis.

Association between valvuloarterial impedance after transcatheter aortic valve implantation and 2-year mortality in elderly patients with severe symptomatic aortic stenosis: the OCEAN-TAVI registry

Pre-procedural valvuloarterial impedance (Zva) is considered as a useful predictor of mortality in patients diagnosed as having severe aortic stenosis (AS) who undergo transcatheter aortic valve implantation (TAVI). However, the prognostic significance of post-procedural Zva remains unclear. We aimed to evaluate the prognostic significance of Zva after TAVI. We retrospectively analyzed the clinical and echocardiographic data of 1004 consecutive elderly patients (median 84 years old, 27.5% men) who underwent TAVI for severe symptomatic AS. Zva was calculated after TAVI, and patients were divided into three groups based on tertile values: the high [> 3.33 (n = 335)], intermediate [2.49-3.33 (n = 334)], and low Zva groups [< 2.49 (n = 335)]. The estimated 2-year all-cause and cardiovascular mortalities using Kaplan-Meier analysis were 16.2% [95% confidence interval (CI) 11.8-20.4] and 5.9% (95% CI 3.2-8.6), respectively. There were no significant intergroup differences in each endpoint (long-rank p = 0.518 for all-cause mortality, p = 0.757 for cardiovascular mortality). Multivariable Cox regression analyzes with adjustments of patient characteristics and medications showed that the post-procedural Zva was not associated with the 2-year all-cause mortality [intermediate Zva group versus (vs.) low Zva group: adjusted hazard ratio (aHR) = 1.34, 95% CI 0.75-2.40, p = 0.316; high Zva group vs. low Zva group: aHR = 1.17, 95% CI 0.64-2.16, p = 0.613] and cardiovascular mortality (intermediate Zva group vs. low Zva group: aHR = 1.50, 95% CI 0.56-4.06, p = 0.421; high Zva group vs. low Zva group: aHR = 1.25, 95% CI 0.43-3.65, p = 0.682). Our results suggest that post-procedural Zva was not associated with 2-year all-cause or cardiovascular mortalities in patients with severe symptomatic AS who underwent TAVI.

Hypertension and transcatheter aortic valve replacement: parallel or series?

Aortic stenosis (AS) is the most common valvular heart disease in the elderly and it causes significant morbidity and mortality. Hypertension is also highly prevalent in elderly patients with AS, and AS patients with hypertension have worse outcomes. Accurate assessment of AS severity and understanding its relationship with arterial compliance has become increasingly important as the options for valve management, particularly transcatheter interventions, have grown. The parameters used for quantifying stenosis severity have traditionally mainly focused on the valve itself. However, AS is now recognized as a systemic disease involving aging ventricles and stiff arteries rather than one limited solely to the valve. Over the last decade, valvuloarterial impedance, a measure of global ventricular load, has contributed to our understanding of the pathophysiology and course of AS in heterogeneous patients, even when segregated by symptoms and severity. This review summarizes our growing understanding of the interplay between ventricle, valve, and vessel, with a particular emphasis on downstream vascular changes after transcatheter aortic valve replacement and the role of valvuloarterial impedance in predicting left ventricular changes and prognosis in patients with various transvalvular flow patterns.